194
Canceling with a Reset: Standby mode is canceled by a reset (power-on or manual). Keep the
RESET
pin low until the clock oscillation settles. The internal clock will continue to be output to
the CKIO and CKIO2 pins.
8.4.3
Clock Pause Function
In standby mode, the clock input from the EXTAL pin or CKIO pin can be halted and the
frequency can be changed. This function is used as follows:
1. Enter standby mode using the appropriate procedures.
2. Once standby mode is entered and the clock stopped within the chip, the STATUS1 pin output
is low and the STATUS0 pin output is high.
3. Once the STATUS1 pin goes low and the STATUS0 pin goes high, the input clock is stopped
or the frequency is changed.
4. When the frequency is changed, an NMI, IRL, IRQ, PINT or on-chip peripheral module
(except interval timer) interrupt is input after the change. When the clock is stopped, the same
interrupts are input after the clock is applied.
5. After the time set in the WDT has elapsed, the clock starts being applied internally within the
chip, the STATUS1 and STATUS0 pins both go low, and operation resumes from interrupt
exception handling.
Summary of Contents for SH7709S
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